Method of decomposing hydrocarbons



Mar. 3, 1925.

' C. F. CROMMETT METHOD oF DEcoMPosING'HYDRocARBoNs original Filed May' 24. 1922 lnvenToT. (Shades FCTornmeTy Patented Mar. .3, 1925.

,UNlTED STATES y 1,528,099 PATENT OFFICE.

vCHARLES F. CRQMMETT, OF CHELSEA, MASSACHUSETTS, ASSIGNOR F ONE-THIRD T0 W'ILFOBDJ.- HAWKINS, OF NEW YORK,

N. Y., AND ONE-THIRD To' LOUIS N.

WHEELOOK, or BOSTON, MASSACHUSETTS.

METHOD 0F D-ECOMPOSING HYDROARBONS.

Application led Kay 24, 1922, Serial No. 563,385.A Renewed January 28. 1925.

To all whom it may concern:

Be it known that I, CHARLES F. CROM- METT, a citizen of the United States, and resident of Chelsea, county of Suffolk, State l of Massachusetts, have invented an Imp-rovement in Methods O Decomposing Hydrocarbons, of which thefollowing description, in connection with the accompanying drawing,` is a specification, like characters on the drawing representing like arts. p This inventionrelates to a method ofi treating hydrocarbons or hydrocarbon compoundsv for the urpose of separating them into their constitutentl elements thereby to form carbon black and gases, or in some cases to formcarbides and gases.

There are two methods now lcommonly employed for producing carbon black from hydrocarbons. One method involves burning the \hydr'ocarbon with an insutlicient amount ofA air thus resulting in the deposit of carbon black,'and the other method involves subjecting the hydrocarbons to a very high heat (13o0 C. to 1700o C.) l

' The rst, or limited combustion method has the disadvantage that it is relatively inefficient as bnly a small percentage of the carbon in the hydrocarbon can be recovered as carbon black.

` .The second,or high temperature meth- Od. also has the disadvantage that it isdiicult to fnd'suitable materials which will withstand the high temperatures required in carrying out thismethod and yet afford a practical means for withdrawing the earbon black when produced.

Furthermore in carrying out this high temperature process it has been found nec- 40 essary to malntain the high temperature for a considerable period of time before the hydrocarbon is broken up into its constituent elements', and this relatively long period of high heat is destructive to the ap aratus which is usually used. y

n object of my present` invention is to provide an improved method for decomposin hydrocarbon by the application of heat y which the desired end can be accomplished more rapidly than in prior methods and at a considerably less temperature than is required in the high temperature process.

Authorities state that when acetylene Lthe hydrogen and carbon place Aat a much `lower temperature than i the (which is a hydrocarbon) is heated in the presence of a suitable catalyzing agent the temperature of dissociation .of the constituents of the acetylene is considerably less than that which is required if the re-a-ction is carried out without the presence of the 50 catalyzer.' p

In practising myinvention I make use of this principle by heating the hydrocarbon compound in the lpresence of a catalyzing agent. Il have found from experiment 05 that it is advantageous to give the catalyzing agent .a fluctuating temperature and my invention, therefore, .involves passin the hydrocarbon compound over a heated catalyzer which has a uctuating temper- 'l0 ature.

For the purpose of giving a better understanding of the invention I have illustrated in the drawings more or less diagrammatic'ally an apparatus which may be used 75 for this purpose. 1

This apparatus consists of a passage or chamber 1 having an inlet 2 forvthe hydrocarbons and an outlet 3.- Saidpassage is adaptedto be heated in some suitable way as by means of a heater 4. The passa e contains a catalyzing agent over which the hydrocarbon passes and in the illustration this catalyzing agent is in the form of a lining 5 foi` the chamber. 6 indicates a 85 scraper movable longitudinally of the chamber -and which may be used for scraping the carbon black from the wallsl of the passage, as it is deposited thereon, said carbon .black `being delivered into a collecting chamber 7 through a passage 8.

When the hydrocarbon is heated in the presence of the catalyzer, as is the case where it is heated in the passage I1 lined witha catalyzing agent, the dissociation of will take catalyzer was not present and will also take placeat a more rapid rate, because of the presence of the catalyzer.

Asstated above the catalyzer may be made of various metals which will have the desired catalyzing effect and the temperature which it `is necessary to employ as well as the length, ot time it is necessary to subject the hydrocarbon to this critical temperature depends somewhat on the character of the catalvzer.

In carrylng out this method it is desirable.

to eliminate entirely from the hydrocarbon `before heated` in the presence of the catalyzer any moisture or other oxygen-producing constituent, because if the hydrocarbon contains such a constituent, the latter becomes decomposed by the heat thus producing free oxygen which will unite with some of the carbon and will consequently decrease the production of carbon black.

The dissociation of the hydrogen and carbon is an endothermic operation, that is one which absorbs heat, and I find by experiment that the temperature in the chamber 1 varies somewhat notwithstanding the application of constant heat thereto, this varying temperature being due to the varying degree of absorption of heat by the dissociation of the gases. The action of the catalyzer is augmented when its temperature fluctuates and my invention contemplates causing a uctuation of the temperature of the catalyzer from outside-sources if it is found desirable to do so to stimulate the catalyzing effect. Such fluctuation can be produced by providing means for electrically heating the My invention, therefore, contemplates not only heating the hydrocarbon in the presence of the catalyzer but also .contemplates doing this with a catalyzer havin a fluctuating temperature, however such uctuation may be secured. i

In carrying out the process the carbon will be deposited on the walls of the passage l as dissociation takes place and the hydrogen or other gasis discharged through the discharge pipe 3 and may be used for any purpose, such Jfor instance as providing heat which can be used in carrying out the process or operate a heat engine or performing any other useful work.

I claim: l

l. The method of forming carbon black which consists in dehydrating a hydrocarbon-mixture and then passing it through a heated assage contaming a catalyzing agent'w ich stimulates the dissociation of the carbon and hydrogen.

2. The method of decomposing a hydrocarbon compound, which consists in passing the compound over a heated catalyzer having a fluctuating temperature.

3. The method of decomposing hydrocarbon which' consists in heating said hydrocarbon in the presence `of a catalyzing agent having a fluctuating temperature.

In testimony whereof, I have signed my name to this 'speciicatiom CHARLES F. CROMMETT. 

